This invention relates generally to push-button control knobs, and more particularly to a method and apparatus for providing rotational and axial control using a push-button control knob.
Control knobs are used on a variety of different devices, perform a variety of different functions and are typically used for controlling automotive systems, such as a radio, for example. Some control knobs have a rotational degree of freedom (rotary type), and have been used to control the volume of an audio system, and others have a translational degree of freedom (slide arrangement), and have been used to control the tone (bass and treble for example) of an audio system. Other control knobs have both rotational and axial (push-button type) degrees of freedom, and have been used to control both the volume and channel balance of a stereo audio system. Multi-functional control knobs provide a degree of convenience for the operator of the controlled device since the operator need only locate one control knob in order to perform more than one function. Push-button-rotary combination control knobs typically employ a control shaft that has both rotational and axial degrees of freedom, thereby requiring a special coupling between the control shaft and the controlled device.
In one embodiment, a push-button control knob having rotational and axial degrees of freedom includes a housing having a first end, a second end, and an integrally arranged hub and rim disposed between the first and second ends. The hub has a central hole and the rim has a plurality of through-holes. An actuator assembly is disposed within the housing and a bias spring is disposed between the housing and the actuator assembly for biasing the actuator assembly in a first direction.
In another embodiment, a method for assembling a push-button control knob having rotational and axial degrees of freedom includes selecting a first actuator plate, grounding the first actuator plate in an orientation in preparation for assembly, selecting a housing in an orientation in preparation for assembly, aligning the axes of the housing and the first actuator plate, assembling the housing onto the first actuator plate, selecting a bias spring in an orientation in preparation for assembly, aligning the axes of the bias spring and the housing, assembling the bias spring onto the housing, selecting a second actuator plate in an orientation in preparation for assembly, aligning the axes of the second actuator plate and the first actuator plate, assembling the second actuator plate onto the first actuator plate, wherein the bias spring is captured between the housing and the second actuator plate, and wherein the first and second actuator plates are coupled together.
In a further embodiment, a push-button control knob having rotational and axial degrees of freedom includes a housing grounded to a shaft and having a rotational degree of freedom, an actuator assembly disposed within said housing and having an axial degree of freedom, and a bias spring disposed between said housing and said actuator assembly for biasing said actuator assembly in a first direction.